This invention relates to explosive devices and more particularly to steam or vapor explosive devices.
Conventional chemical explosives are frequently sensitive to heat and impact. Moreover, they generally yield toxic fumes when they burn as in a fire. Thus, these conventional explosives require special handling and storage precautions.
A phenomena of considerable industrial importance in recent years and one that may have significant military application is the so called vapor explosion, often referred to as thermal explosion or steam explosion. This phenomena results from the extremely rapid heat transfer from hot liquid (e.g., molten metal) when introduced into cold liquid (e.g., water). Sporadic explosions resulting from this phenomena have been responsible for loss of life and property in industry for a number of years and efforts have been made to understand the extreme violence of these interactions. It is not presently known exactly how these explosions are initiated. However, resultant effects of these interactions are drastic, and substantial amounts of energy are released during such explosions.
U.S. Pat. No. 4,280,409, entitled "Molten Metal-Liquid Explosive Device," which issued to Alexander G. Rozner and Horace H. Helms on July 28, 1981, discloses an explosive device which comprises
(1) a metal liner composed of a metal selected from the group consisting of aluminum, magnesium, copper, and brass, the liner enclosing a chamber;
(2) a liquid contained in the chamber;
(3) a layer of pyrotechnic material surrounding the outside of the liner, the pyrotechnic material composed of a mixture of powders of (a) nickel; (b) metal oxide; and (c) an aluminum containing component which may be (i) aluminum or (ii) a mixture of from 50 to less than 100 weight percent of aluminum and from more than zero to 50 weight percent of a metal which can be magnesium, zirconium, bismuth, beryllium, boron, tantalum, copper, silver, niobium, or mixtures thereof; and
(4) means for igniting the pyrotechnic material. The devices are compact, self-contained, safe, high energy explosives having relatively short initiation to detonation times. Nevertheless the devices work by the flowing contact of the molten pyrotechnic reaction products and the liquid (e.g., water). It would be desirable to provide a device in which the molten pyrotechnic reaction products are propelled into the liquid, thus reducing the initiation to detonation time and increasing the violence of the explosion. At the same time, it is desirable to retain the advantages of compactness and safety of the device.